Carbon materials are conventionally utilized for catalyst carriers, adsorbents, separator agents, ink, toner or the like, and advents of nano-carbon materials having nano-sized dimensions such as carbon nanotube, carbon nanohorn and the like in recent years draw attentions for the characteristic thereof as the structural body, and studies for applications thereof are earnestly carried out.
In particular, characteristic structures of such carbon nanotube and carbon nanohorn attract attentions for industrial catalyst carriers, and for example, are described in the following Patent Literature 1 as one of the optimum catalyst carriers, and have been recently utilized for catalyst carriers of fuel cells.    Patent Literature 1; Japanese Patent Laid-Open No. 2004-152,489